Jimmy Soni over at substack has written a story on X.com. Single character length domains were banned in the late 90s but x.com first saw light in 1993.
Early in the creation of his second start-up, Musk had conviction about its name: X.com. This was, Musk believed, simply “the coolest URL on the internet.”
He wasn’t the only one who believed so. In the early 1990s, a pair of engineers, Marcel DePaolis and Dave Weinstein, had purchased www.x.com for their company Pittsburgh Powercomputer. Their original URL — www.ppc.com — had been taken from them when the contract for managing URL DNS information was taken over by a company called Network Solutions. So they decided to call up Network Solutions and explore other URL options — which is when they discovered that X.com was available.